Shortly after midnight, an officer on general patrol was flagged down by a man on Pinehurst Line outside of Chatham in regards to a serious single motor vehicle collision.
Chatham-Kent police officials say emergency crews responded and the 38-year-old Richmond Hill man and 48-year-old Chatham woman were transported to the Chatham-Kent Health Alliance for medical attention.
The woman has since been transferred to London with life-threatening-injuries.
The collision remains under investigation.
Anyone with information is asked to contact Constable Doug Cowell at firstname.lastname@example.org or 519-355-1092.